Influence of Nanosilica on the Vibro-acoustic Behavior and Morphological Characteristics of Wood Flour/ Recycled Polystyrene Composites

Abstract

This study investigated the influence of nanosilica on the vibro-acoustic behavior, microstructure, and structural characteristics of composites based on poplar wood flour and recycled polystyrene. Composites containing 50 wt% wood flour and 0, 2, 4, and 6 phc nanosilica were prepared using twin-screw extrusion. Vibro-acoustic properties were evaluated using a non-destructive flexural vibration method, while the fractured-surface morphology and diffraction characteristics were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Nanosilica caused only minor changes in sound velocity, loss tangent, acoustic coefficient, acoustic conversion efficiency, and dynamic modulus of elasticity, with no statistically significant differences among the formulations (p > 0.05). SEM images showed apparent reductions in interfacial voids and improved contact between the wood flour and polymer matrix with nanosilica incorporation. XRD patterns indicated that the composites retained a predominantly amorphous character, while the changes in diffraction intensity suggested differences in X-ray scattering following nanosilica incorporation. Overall, nanosilica altered the apparent microstructural characteristics of the composites without significantly affecting their vibro-acoustic performance. The combination of stable vibro-acoustic properties and the use of recycled polystyrene suggests potential for these composites in lightweight panel and interior applications where stable acoustic behavior is desirable.